Sheet metal brake

ABSTRACT

The brake for bending sheet material disclosed herein comprises a pair of spaced base rails on which C-shaped members are positioned at longitudinally spaced points. A first member is fixed on the lower arms of the C-shaped members and has a clamping surface. A second member having a bending surface is hinged to the first member. An anvil member is interposed between the anvil member and the upper arms of the C-shaped members. The pressure member has wedges thereon which function when the pressure member is translated longitudinally to apply pressure to the anvil member. A handle is pivoted to the first member at one end and is operatively connected to the pressure member for shifting the pressure member. Novel means are provided between the wedges and the anvil member for adjusting the pressure along the anvil member.

[ SHEET METAL BRAKE [75] Inventors: Walter G. Marsh, Birmingham;

James J. Rhoades, Westland, both of Mich.

[73] Assignee: Tapco Products Company, Inc., Detroit, Mich.

221 Filed: Mar. 1, 1973 21] Appl. No.: 336,991

[52] U.S. Cl. 72/319, 72/310 [51] Int. Cl B2ld 11/04 v [58] Field of Search 72/319, 310, 316, 318,

[56] References Cited UNITED STATES PATENTS Rauen et a1 Smith 72/319 1 June 18, 1974 Primary Examiner-Charles W. Lanham Assistant ExaminerM. J. Keenan Attorney, Agent, or Firm-Barnes, Kissel le, Raisch & Choate 57 ABSTRACT The brake for, bending sheet material disclosed herein.

comprises a pair of spaced base rails on which C- shaped members are positioned at longitudinally spaced points. A first member is fixed on the lower arms of the C shaped members and has a clamping surface. A second member having a bending surface is hinged to the first member. An anvil member is interposed between the anvil member and the upper arms of the C-shaped members. The pressure member has wedges thereon which function when the pressure member is translated longitudinally to apply pressure to the anvil member. A handle is pivoted to the first member at one end and is'operatively connected to the pressure member for shifting the pressure member. Novel means are provided between the wedges and the anvil member for adjusting the pressure along the anvil member.

10 Claims, 4 Drawing Figures SHEET METAL BRAKE This invention relates to brakes for bending sheet material such as aluminum sheet and vinyl sheet that is utilized for application as siding for buildings and the like.

In the prior US. Pat. Nos. 3,161,223 and 3,559,444, there are'disclosed and claimed sheet metal bending brakes wherein sheet metal is clamped between an anvil member and a clamping surface and a bending member is hinged for bending the sheet metal about the anvil member. Such sheet metal bending brakes are often subjected to extremely severe handling conditions and, as a result, wear and misalignment may occur which results in variation in the force with which the sheet metal is clamped along the length of the anvil member.

Accordingly, among the objects of this invention are to provide a sheet metal bending brake where the clamping force can be varied readily along the lengt of the anvil member.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of a sheet metal bending brake embodying the invention.

FIG. 2 is a fragmentary sectional view taken along the line 2-2 in FIG. 1.

FIG. 3 is a fragmentary sectional view taken along the line 33 in FIG. 2.

FIG. 4 is an end view of a part of the sheet metal brake embodying the invention.

DESCRIPTION Referring to FIGS. 1 and 2, the sheet bending brake embodying the invention comprises a pair of spaced inverted channel members 10, 11 formed of aluminum extrusions and longitudinally spaced C-shaped members 12 comprising aluminum castings bolted to the rails 10, 11. Each C-shaped member 12 includes a lower arm 13, an upper arm 14 and an intermediate portion 15. The lower arms 13 are bolted to the rails 10, 11. Afirst member 16 in the form of an inverted channel is fixed on the lower leg 13 and a second channel 17 is hinged along one edge to the channel 16. Members 16, 17 are formed with mating integral projections 18, 19 along their adjacent longitudinal edges that are made by machining the edges along flat transverse planes. The projections are provided with aligned openings 20 and a hinge pin 21 is inserted in the openings to complete the hinge.

The upper surface 22 of member 16 provides a clamping surface and a generally L-shaped anvil member 23 is provided in overlying relation to the clamping surface 22 of the member 16. The anvil member 23 includes a sharp longitudinally extending edge 24 adjacent the hinge line.

A pressure or backing plate 25 is provided in overlying relationship to the anvil member 23 and has inclined cams or wedges 26 fixed at longitudinally spaced points thereon in overlying relationship to the arms 14 of C-shaped members 12. The pressure member 25 is adapted to be moved longitudinally by an arrangement which includes a bracket 27 fixed on the member 16 at one end. An operating handle or lever 28 is pivoted at its lower end to the bracket 27 and intermediate its ends to a bracket 29 extending from a block 30 on the pressure member 25. By shifting the lever inwardly or toward the left as viewed in FIG. 1, the pressure member 25 is moved to wedge the pressure member downwardly onto. the anvil member 23 to clamp a piece of sheet material S between the anvil member 23 and the first member 16.

Spring plates 31 are fixed to each upper arm l4and extend between brackets 32 fixed on the anvil member 23 to tend to elevate the anvil member 23 when the cams 26 are moved to the right as viewed in FIG. 1.

The anvil member 23 and pressure member 25 have cooperating generally V-shaped ribs 33, 34 and valleys 35, 36 which extend longitudinally between the edges thereof for guiding the movement of the pressure member relative to the anvil member.

As shown in FIG. 1, the ends of the anvil member 23 and pressure member 25 extend beyond the end of the first member 16 sufficiently so that when the pressure member 25 is moved to the right to relieve the pressure on the anvil member no portion of the end of the pressure member extends beyond the end of the anvil member. This insures that the pressure member will not become bent or damaged and will at all times remain straight insuring a uniform pressure on the sheet material.

When a piece of sheet material such as aluminum sheet metalis to be bent, the lever 28 is swung to the right as viewed in FIG. 1 to relieve the clamping pressure and to elevate the anvil member 23. The sheet material is then inserted in proper position between the member 16 and anvil member 23 and the lever 28 is moved to the left as viewed in FIG. 1 to clamp the sheet metal. The member 17 is then swung upwardly through a handle, not shown, to bend the sheet material to the desired angle.

In order to prevent marring and scratching of the flat surface 19a of the bending member 17, an appropriate wear resistant surface may be provided, for example, by the well-known means of a vinyl strip 37 slidably received in a channel 38. The upper surface of the vinyl strip is flush with the surface 19a.

In accordance with theinventiion, means are provided for selectively adjusting the pressure at each wedge 26 and comprises a vertical threaded opening 40 in each wedge intermediate its ends and a nylon screw 41 having a rounded end 42 threaded therein. By threading screw 41 inwardly through an aligned opening 43 in pressure member 25, the rounded end 42 of screw 41 engages a flat horizontal portion of the anvil member 23, thereby moving the anvil member 23 away from the pressure member 25 so that when the wedge is cammed or wedged the pressure at that point is increased. By threading the screw outwardly, the pressure can be decreased. It is thus possible to selectively member to clamp a workpiece on the clamping surface of said first member,

said last-mentioned member having wedge means thereon,

means mounted on said first member for shifting said pressure member longitudinally to engage said wedge means,

adjustable means extending between the wedge means and the anvil member for varying the pressure of the pressure member on the anvil member.

2. The combination set forth in claim 1 wherein said last-mentioned means comprises an opening through said pressure member, a threaded opening in said wedge means, and a screw threaded into said threaded opening and extending through said opening in said pressure member into engagement with said anvil member.

3. The combination set forth in claim 2 wherein the end of said screw engaging said anvil member is rounded.

4. The combination set forth in claim 3 wherein said screw is made of low-friction material.

5. The combination set forth in claim 4 wherein said material comprises nylon. 6. In a brake for bending sheet metal, the combination comprising a pair of spaced base rails, a plurality of C-shaped members positioned on said base rails at longitudinally spaced points, each said C-shaped member comprising a lower arm fixed to said rails and an upper arm spaced from and overlying said lower arm, a first member fixed on the lower arms of said C- shaped members and having a clamping surface, an anvil member, means for locking said anvil member on said first member to clamp a piece of sheet metal between said anvil member and said clamping surface of said first member,

a second member having a bending surface,

said first and second members having longitudinally spaced integral intermeshing projections extending outwardly along substantially the entire length of the longitudinal edges thereof,

each said projection of each said member being positioned such that all portions thereof do not extend above the plane of the surface of its corresponding member when the surfaces are substantially aligned, I

said projections having aligned openings,

a hinge pin extending through said openings to define a hinge,

said anvil member having a longitudinal edge extending along said hinge line,

said means for clamping said anvil member against said first member including wedge means between said upper arms of said C-shaped members and said anvil member,

means for shifting said pressure member longitudinally to engage said wedge means,

adjustable means extending between the wedge means and the anvil member for varying the pressure of the pressure member on the anvil member.

7. The combination set forth in claim 6 wherein said last-mentioned means comprises an opening through said pressure member, a threaded opening in said wedge means, and a screw threaded into said threaded opening and extending through said opening in said pressure member into engagement with said anvil member.

8. The combination set forth in claim 7 wherein the end of said screw engaging said anvil member is rounded.

9. The combination set forth in claim 8 wherein said screw is made of low-friction material.

10. The combination set forth in claim 9 wherein said material comprises nylon. 

1. In a brake for bending sheet material, the combination comprising a first member having a clamping surface, a second member having a bending surface, means for hinging said second member to said first member, an anvil member extending longitudinally of said first member, a pressure member extending longitudinally of said anvil member for applying pressure to said anvil member to clamp a workpiece on the clamping surface of said first member, said last-mentioned member having wedge means thereon, means mounted on said first member for shifting said pressure member longitudinally to engage said wedge means, adjustable means extending bEtween the wedge means and the anvil member for varying the pressure of the pressure member on the anvil member.
 2. The combination set forth in claim 1 wherein said last-mentioned means comprises an opening through said pressure member, a threaded opening in said wedge means, and a screw threaded into said threaded opening and extending through said opening in said pressure member into engagement with said anvil member.
 3. The combination set forth in claim 2 wherein the end of said screw engaging said anvil member is rounded.
 4. The combination set forth in claim 3 wherein said screw is made of low-friction material.
 5. The combination set forth in claim 4 wherein said material comprises nylon.
 6. In a brake for bending sheet metal, the combination comprising a pair of spaced base rails, a plurality of C-shaped members positioned on said base rails at longitudinally spaced points, each said C-shaped member comprising a lower arm fixed to said rails and an upper arm spaced from and overlying said lower arm, a first member fixed on the lower arms of said C-shaped members and having a clamping surface, an anvil member, means for locking said anvil member on said first member to clamp a piece of sheet metal between said anvil member and said clamping surface of said first member, a second member having a bending surface, said first and second members having longitudinally spaced integral intermeshing projections extending outwardly along substantially the entire length of the longitudinal edges thereof, each said projection of each said member being positioned such that all portions thereof do not extend above the plane of the surface of its corresponding member when the surfaces are substantially aligned, said projections having aligned openings, a hinge pin extending through said openings to define a hinge, said anvil member having a longitudinal edge extending along said hinge line, said means for clamping said anvil member against said first member including wedge means between said upper arms of said C-shaped members and said anvil member, means for shifting said pressure member longitudinally to engage said wedge means, adjustable means extending between the wedge means and the anvil member for varying the pressure of the pressure member on the anvil member.
 7. The combination set forth in claim 6 wherein said last-mentioned means comprises an opening through said pressure member, a threaded opening in said wedge means, and a screw threaded into said threaded opening and extending through said opening in said pressure member into engagement with said anvil member.
 8. The combination set forth in claim 7 wherein the end of said screw engaging said anvil member is rounded.
 9. The combination set forth in claim 8 wherein said screw is made of low-friction material.
 10. The combination set forth in claim 9 wherein said material comprises nylon. 